ok so i dont want to get into this pissing match, but seriously, i want to install an efan on my truck just because of the water crossings i do my clutch fan turns into a boat prop. is there any cons to having an efan that will really concern me? im not doin it for power gain or milage
Since an e-fan will have less capacity than a mechanical fan you'll lose some cooling capacity in the switch. Will that matter? Depends. Pretty much everything on your truck has some kind of margin that allows for wear and tear without an actual breakdown. Your fan and radiator are designed to have sufficient cooling capacity to keep the vehicle from overheating under the worst conditions.
High load, low speed, bad coolant, lots of dirt and crap on your radiator fins, and high ambient temp are all factors that will diminish your cooling capacity. If you run into all of them (or just several of them) at once you risk overheating.
Mechanical fans have the big advantage that when all else fails, you can shift into neutral and rev the engine to force a cool down.
If you don't have a problem running hot and you keep your radiator clean, you should be ok with an e-fan.
Another option for water crossing is some sort of baffle or deflector behind the top of the engine fan to keep most of the water off the top of the engine. But make sure it doesn't restrict air flow across things that need it, like the alternator.